Methoxymethyl-triphenylphosphonium chloride → 1-(2,6-dichloro-phenyl)-4-isopropyl-5-[4-(2-methoxy-vinyl)-3-methyl-phenoxymethyl]-1H-pyrazole

Participants

Reaction Steps

To an ambient temperature suspension of potassium tert-butoxide (668 mg, 5.96 mmol) in THF (20 mL) is added (methoxymethyl)triphenyl phosphonium chloride (2.04 g, 5.96 mmol) and is stirred at room temperature for 20 min. Solid 4-[2-(2,6-Dichloro-phenyl)-4-isopropyl-2H-pyrazol-3-ylmethoxy]-2-methyl-benzaldehyde (400 mg, 0.992 mmol) is added and the reaction is stirred at room temperature overnight. The reaction is quenched with sat. aq. NH4Cl and concentrated. The residue is partitioned between Et2O and water. The aqueous layer is extracted with Et2O and the combined organic layers are washed with brine, dried (MgSO4), filtered, concentrated and chromatographed (SiO2 120 g, 0% to 30% EtOAC/Hex) to yield the title compound (302 mg, 73%) as a mix of E/Z isomers. 1H NMR (400 MHz, CDCl3) (major isomer) δ 7.70 (s, 1H), 7.43-7.38 (m, 2H), 7.33-7.26 (m, 1H), 7.08 (d, 1H, J=8.4 Hz), 6.72 (d, 1H, J=12.8 Hz), 6.60-6.52 (m, 2H), 5.82 (d, 1H, J=12.8 Hz), 4.78 (s, 2H), 3.66 (s, 3H), 3.00 (sept, 1H, J=7.0 Hz), 2.22 (s, 3H), 1.30 (d, 6H, J=7.0 Hz).

Provenance & Evidence